One method for connecting a flexible polymeric hose to a metal tube or tube fitting is to provide one or more grooves on a nipple formed by the end of the tube or as part of the tube fitting. The nipple is inserted into an open end of the flexible hose and, in some applications, one or more O-rings may be installed in respective grooves in the nipple to provide a high pressure seal against the escape of fluid, such as refrigerant, through the connection. A tubular shell surrounding the hose end and nipple is then crimped to secure the hose to the nipple.
While such design provides a leak free coupling, some drawbacks are associated therewith. One problem is making sure the O-ring or O-rings are not dislodged from the grooves while the nipple is being inserted into the hose, so that the seals will be in the proper place prior to crimping of the shell. Another disadvantage is the need to form the groove or grooves in the nipple. If done by machining, the nipple will require proper cleaning to remove any metal debris. If not removed, the debris may create a leak path.